Predatory ladybugs eat mites, thrips, fruit flies and scale insects in addition to aphids. Plant-eating species feed on the leaves of corn, potatoes and grains, but are not considered major crop pests.
There are over 5,000 species of ladybugs. Most of them have oval, dome-shaped bodies and red to yellow coloration with black spots. Their bright colors announce the presence of chemicals that are distasteful to predators. Ladybugs help control many crop pests and can be bought from garden supply firms catering to organic gardeners. In popular culture, the ladybug is an omen of good luck and is the state insect of Tennessee, Delaware, Massachusetts, Ohio and New Hampshire.